members of the senate intelligence committee are asking why they didn't know the fbi was investigating david petraeus until the cia director resigned. >> we received no advance notice. it was like a lightning bolt. >> reporter: fbi officials say they did not alert lawmakers or the white house because they weren't turning up evidence of a crime or security breach, but retired general richard meyers told cbs this morning with investigations of this nature notifying superiors is common. >> we saw lots of investigations in the military where the allegations were not proven yet, but that the chain of command was made aware that somebody was being looked at for whatever. >> reporter: before the scandal petraeus had been scheduled to testify this week on capitol hill about the deadly attack on the u.s. consulate in benghazi, libya. acting cia director mike morrell will testify instead. >> from my point of view it's absolutely essential that he give testimony before the congress so we can figure out benghazi. >> reporter: the fbi uncovered petraeus' extramarital fair with his biographer paula